Is there a way to create a Color ID map in Blender?
It's possible to export the ID color map straight from UV/Image editor without baking it by using this addon. It's fast and writes the UV layout into a png file, filling the polys with the color assigned in the viewport color slot:


Set the viewport colors for all materials:





Go to UV/Image Editor > UVs > Export Colour Layout:




Result:





Original thread (www.polycount.com):


  Blender Export Colour Layout Addon - 
  This is an addon for Blender that enables the exporting to png the unmodified diffuse colors of applied materials using the meshes uv map as a layout. In essence it generates a colour ID map for use in applications such as Quixel Suite DDO. As it does not use baking it is easier and quicker to generate colour ID map, it also (appears) to work the same regardless of whether you are using Blender Renderer or Blender Cycles. It is heavily based on the original UV Layout addon and is still a work in progress, but it exports the colour map just fine. In the future I'd love to work out a method of assigning DDO colour link id's to Blender materials and export those, instead of having to set the materials diffuse colour. The download has a brief read me with more details in it. If you have any problems with the addon feel free to post them in this thread and I'll see if there is anything I can do to help. I'm unsure if not going the baked approached means that something important is missing. As far as I can tell uv islands are not anti-aliased, but materials that share the same edges are and that appears to work fine within DDO.